With the spread of electric vehicles and plug-in hybrid vehicles in recent years, wireless charge systems have been developed which are configured to wirelessly supply power to a vehicle coil mounted on a vehicle. Here, such wireless charge systems require high parking accuracy in order to improve the efficiency of charge between a vehicle coil and a ground coil.
In view of this, a parking assistance system disclosed in Japanese Patent Application No. 2011-15549 detects the distance between a ground coil and a vehicle coil by supplying lower power than normally supplied power from the ground coil to the vehicle coil after the ground coil gets under the vehicle body and the ground coil can no longer be imaged by a camera. The parking assistance system then displays a mark indicating the vehicle coil and a mark indicating the ground coil on a display unit and reflects the detected distance between the coils on the distance between the marks to thereby provide assistance for accurate parking of the vehicle.
However, the conventional parking assistance system mentioned above merely detects the distance between the ground coil and the vehicle coil, and therefore has a problem in that the positions of the ground coil and the vehicle coil can be aligned with each other but their angles cannot be aligned with each other. In particular, in a case of using solenoid type coils as the ground coil and the vehicle coil, a difference in angle therebetween drastically lowers the charge efficiency. Hence, a different in angle between the ground coil and the vehicle coil has been a problem.